It often occurs after a negative life event. However, unlike “sadness” or “disappointment” (normal reactions to negative life events) MDD is characterized by very strong negative feelings that last for a long time. Because these feelings are too strong and last for too long they don’t help or motivate people to find out what’s wrong, cope with the problem, make decisions – and then get on with life. Instead, these strong negative feelings interfere with our ability to cope and make decisions.